function Person(){
    this.pername = 'humen'
}
Person.prototype.getPerson = function(){
    console.log(this.pername)

}
function Doctor(){
    this.docname = 'doctors'
}
Doctor.prototype = new Person()
Doctor.prototype.getPerson = function(){
    return false;
}
var doctor = new Doctor()
console.log(doctor.__proto__)
console.log(doctor.getPerson())
